The increasing interest of meteorological, climatic, and hydrological scientific communities in the different components of the surface energy balance, and particularly in the evapotranspiration, has encouraged the development of different micro-meteorological models for estimating surface energy fluxes at a local scale. Recent advances in satellite remote sensing techniques may allow the monitoring of these surface energy fluxes over extensive areas. However, most of the current models require in situ calibration or empirically derived parameters, which limit their operational application at a large scale. The objective of this work is to present a micro-meteorological approach that can be operationally used together with satellite images to monitor surface energy fluxes at a regional scale. Firstly, we introduce the framework and details of the proposed micro-meteorological model, which is based on a two-source patch representation of the soil-canopy-atmosphere system. The feasibility of the model is explored at a local scale using data collected over two completely different ecosystems. On the one hand, data collected over a maize (corn) crop in Beltsville, Maryland, USA, during the 2004 summer growing season. On the other hand, data from an experimental campaign carried out in a boreal forest in Finland in 2002. Comparison of the results with ground measurements shows errors between 15 and 60 W m-2 for the retrieval of net radiation, soil heat flux, and sensible and latent heat fluxes in both sites.
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